Demo of PBR in CityEngine?

[NicolaiSteinø]

While I have done some classic shading work in CE, I'm interested in the new PBR shading capability. Could someone possibly do a demo or a rundown of the essentials of PBR in CE? I'm in architecture and I'm intersted in learning how to set up realistic textures. But there are so many material attributes and material maps, it's a bit of a maze for me. And even after researching some generic PBR info, it doesn't seem to translate directly to the concepts used in CE. While PBR concepts like Albedo, AO, are not concepts in CE, CE concepts like opacity, emissive and occlusion are not concepts in PBR. Or are they just different names for identical/similar things?

[CherylLau]

Here is how the CGA material attributes correspond to the GLTF material spec based on Physically-Based Rendering (PBR).

CGA material attributes

material shape attributes—ArcGIS CityEngine Resources | Documentation 

GLTF material spec

https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#reference-material

CGA material attributes	GLTF material spec
material.color.{r|g|b}	pbrMetallicRoughness.baseColorFactor, RGB components
material.opacity	pbrMetallicRoughness.baseColorFactor, A component
material.colormap	pbrMetallicRoughness.baseColorTexture, RGB channels
material.opacitymap	pbrMetallicRoughness.baseColorTexture, A channel
material.metallic	pbrMetallicRoughness.metallicFactor
material.roughness	pbrMetallicRoughness.roughnessFactor
material.metallicmap, B channel	pbrMetallicRoughness.metallicRoughnessTexture, B channel
material.roughnessmap, G channel	pbrMetallicRoughness.metallicRoughnessTexture, G channel
material.normalmap	normalTexture
material.occlusionmap, R channel	occlusionTexture, R channel
material.emissivemap	emissiveTexture
material.emissive	emissiveFactor
material.opacitymap.mode	alphaMode
material.opacitymap.cutoff	alphaCutoff

Demo Project

The zip file attached (PBR_Demo.zip) is a CityEngine demo project that sets PBR materials in CGA.

[Kristian-Mortensen91]

I have downloaded a material from Quixel, and there is four pictures, an albedo, a displacement, a Normal and a Roughness map. I have made the albedo and the normal map work but is unsure on how to make the two other maps work. This is the code so fare:

brickMap01 = "/CityVR_2/assets/textures/PBR/Wall/Brick/Brick_Modern_ufoqbe2g_2K_surface_ms/ufoqbe2g_2K_Albedo.jpg"
bumpMap01 = "/CityVR_2/assets/textures/PBR/Wall/Brick/Brick_Modern_ufoqbe2g_2K_surface_ms/ufoqbe2g_2K_Displacement.jpg"
normalMap01 = "/CityVR_2/assets/textures/PBR/Wall/Brick/Brick_Modern_ufoqbe2g_2K_surface_ms/ufoqbe2g_2K_Normal.jpg"
roughnessMap01 = "/CityVR_2/assets/textures/PBR/Wall/Brick/Brick_Modern_ufoqbe2g_2K_surface_ms/ufoqbe2g_2K_Roughness.jpg"

WallMaterial01 -->
set(material.colormap.su,1/1.440)
set(material.colormap.sv,1/1.440)
set(material.colormap,brickMap01)
set(material.normalmap.su,1/1.440)
set(material.normalmap.sv,1/1.440)
set(material.normalmap,normalMap01)
set(material.roughnessmap.su,1/1.440)
set(material.roughnessmap.sv,1/1.440)
set(material.roughnessmap, roughnessMap01)
projectUV(0)